Generally, devices disclosed in Japanese Unexamined Utility Model Application Publication No. S53-121573, Japanese Examined Patent Application Publication No. H2-23412, Japanese Unexamined Patent Application Publication No. H4-40254, Japanese Unexamined Patent Application Publication No. H10-15887, and Japanese Unexamined Patent Application Publication No. 2002-211833 can be mentioned as examples of this type of film cutting device. These film cutting devices are used to cut a continuous belt-like film into predetermined lengths while drawing the film from a roll, so as to package various articles of merchandise with the film.
Japanese Unexamined Utility Model Application Publication No. S53-121573 relates to a thin-paper rotary cutting device comprised of convex blades and flat receiving blades, in which the convex blade is formed to have a concavely curved shape, and cuts a thin sheet of paper in a state of being slightly inclined with respect to the flat receiving blade, thereby making its blade touching uniform.
Japanese Examined Patent Application Publication No. H2-23412 relates to a device for cutting a film with a cutting knife provided on an adsorption drum and with a rotary opposed knife while winding the film drawn out on the adsorption drum, in which neither jamming nor a positional deviation occurs when the film is cut, because the film is cut in the state of being adsorbed onto the adsorption drum.
As in Japanese Examined Patent Application Publication No. H2-23412, Japanese Unexamined Patent Application Publication No. H4-40254 relates to a device in which a film is cut while winding the film on a roller, so that neither jamming nor a positional deviation occurs when the film is cut.
Japanese Unexamined Patent Application Publication No. H10-15887 relates to a cutting device in which a lower blade of a rotary cutter is caused to depart from a position to butt against an upper blade and is elastically deformed when a sheet of paper or the like is cut, so that a cutting operation is performed with the lower and upper blades by means of an elastic return force generated by the toughness of the lower blade.
Japanese Unexamined Patent Application Publication No. 2002-211833 relates to a device for cutting a narrow tear tape being fed to packaging sheets, in which a slope cutter that serves as a receiving blade is provided at the middle of a conveying adsorption belt that conveys a tape, and the time during which a tape is not adsorbed is shortened by cutting the tape in the vicinity of a film-conveying plane that meets the tape, thereby preventing the tape from being crumpled so that the tape can be conveyed straight.
However, with regard to the film cutting device mentioned above, that of Japanese Unexamined Utility Model Application Publication No. S53-121573 has a disadvantage in that the convex blade cannot be easily formed to have a concavely curved shape, and it is difficult to adjust the blade butting between the convex blade and the flat receiving blade. That of Japanese Examined Patent Application Publication No. H2-23412 and that of Japanese Unexamined Patent Application Publication No. H4-40254 have a disadvantage in that the adsorbing device must be provided not only on the conveying belt but also on the adsorption roller, and the film is wound on the adsorption roller and is drawn out toward the deflection roller, thus increasing the number of rollers and producing a complex, high-cost device. That of Japanese Unexamined Patent Application Publication No. H10-15887 has a disadvantage in that a blade-touching adjustment is difficult since the blade is elastically deformed by the toughness of the blade when a film or the like is cut.
That of Japanese Unexamined Patent Application Publication No. 2002-211833 is a device for cutting a narrow tear tape, and cannot cut a packaging film much wider than the tear tape with high precision. Especially when two blades are provided in a crossed manner, and a cutting edge of one of the two blades is butted against a cutting edge of the other blade so as to cut a film in point contact as if with a pair of scissors, a blade width becomes greater, and, unlike the tear tape, the width of the film to be cut becomes greater. Therefore, the cutting edge largely departs because of its blade toughness, and, disadvantageously, a precise cutting operation cannot be performed.
The present invention has been made in consideration of these circumstances, and aims to provide a film cutting device capable of easily performing a blade touching adjustment and capable of cutting any kind of film with high accuracy even if the film is wide.